The Hong Kong based hedge fund Oasis Investments returned 9.37% net of fees last year, bringing annualized returns for flagship funds to 18.50% since inception in 2002 with annualized volatility of 12.95% and an impressive Sharpe ratio of 1.32. The fund’s YTD performance (the letter is dated March 26) is 2.70%, and Oasis Investments CIO Seth Fischer is excited about investments in Japan that take advantage of the ‘ROE revolution’ going on there. “In these past few years, 60-70% of our P&L has been in Asia –ex Japan including greater China. We are spending our time focusing on this, and we…